Anorexia Nervosa:
Those who are suffering with this illness have a low self-esteem and often a tremendous need to control their surroundings and emotions. The Eating Disorder, Anorexia, is a unique reaction to a variety of external and internal conflicts, such as stress, anxiety, unhappiness and feeling like life is out of control. Anorexia is a negative way to cope with these emotions. New research indicates that for a percentage of sufferers, a genetic predisposition may play a role in a sensitivity to develop Anorexia, with environmental factors being the trigger.
The person suffering with Anorexia may be abnormally sensitive about being perceived as fat, or have a massive fear of becoming fat -- though not all people living with Anorexia have this fear. They may be afraid of losing control over the amount of food they eat, accompanied by the desire to control their emotions and reactions to their emotions. With a low self-esteem and need for acceptance they will turn to obsessive dieting and starvation as a way to control not only their weight, but their feelings and actions regarding the emotions attached. Some also feel that they do not deserve pleasure out of life, and will deprive themselves of situations offering pleasure (including eating).

Source:http://www.something-fishy.org/